Latex agglutination is a well known and established immuno-assay test. The basis for the technique lies in the ability to coat latex spheres (300-800 nm in diameter) with a specific antibody. If the spheres are exposed to a sample containing the relevant antigen then bonding can occur leading to clumping of the latex balls. An alternative form of the test uses latex spheres coated in antigen, samples can then be tested for the presence of the relevant antibody.
Traditionally the test has been carried out manually by transferring quantities of control and test latex from phials within a reagent kit, to a piece of black card, and mixed with the sample to be tested. Agglutination of the latex balls can be clearly seen against the dark background.
It is also known to perform a biological assay by filling a cuvette with a plurality of small diameter spheres (typically of latex) coated with a specific binding agent and to add a sample material to the cuvette and observe whether there is any change in the light scattering properties of the contents of the cuvette as a result of any binding of the sample to the spheres. The change in light scattering properties is brought about by the increased diameter of the spheres due to the binding of the sample material thereto, and if there is binding, then the sample is assumed to contain the specific binding partner of the material on the spheres.
It is one object of the present invention to provide an improved cuvette by which such an assay can be performed.
It is another object of the present invention to provide an improved analyser for performing assays using such cuvettes and which performs a verifying test on a cuvette before a biological assay is performed.
It is a further object of the invention to provide an improved method of performing a biological assay.